Wakeful Resting Linked To Improved Memory

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Main Category: Neurology / Neuroscience
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Article Date: 01 Feb 2010 - 9:00 PST

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New research from the US shows that resting while awake appears to strengthen memory, revealing new insights into how forms of rest other than sleep, affect the memory consolidation process. The findings suggest that even though it may not look like it, when we rest while awake, our brains are still working, something we may find hard to accept in an information technological world that is on the go 24/7.

You can read about the findings of the study, by Dr Lila Davachi, an assistant professor in the Department of Psychology and Center for Neural Science at New York University, and colleagues, in the 28 January issue of the journal Neuron.

Davachi, in whose lab the research was conducted, told the press that:

"Taking a coffee break after class can actually help you retain that information you just learned."

"Your brain wants you to tune out other tasks so you can tune in to what you just learned," she explained.

Lead author Arielle Tambini, a doctoral candidate in NYU's Graduate School of Arts and Science, said the study focused on memory consolidation, which occurs during the stabilizing period just after a memory is initially formed or encoded.

The third co-author of the study was Nicholas Ketz, a research assistant in the Department of Psychology at NYU.

The hippocampus is an important region of the brain for forming episodic memories (memories tied to particular events, including times, places, emotions and associations that occured at the time) as opposed to procedural memories (for instance learning to play a musical instrument).

Without the hippocampal part of the memory forming process you could for instance learn to play the flute but then not remember the times and places where your lessons took place or how you felt on those occasions.

There is a theory that long term storage of episodic memories is a process of "offline transfer" of information from the hippocampus to the neocortex, which creates a cortical-based representation of the memory that is independent of the hippocampus.

However, until now, no studies have shown a link between off-line hippocampal-cortical interactions and long-term memory.

Previous studies have shown that some regions of the brain are more active during periods of rest, but not tried to link them with memory.

For the study, Tambini, Davachi and colleagues tasked volunteers to look at pairs of images, without telling them they would later be asked to recall them. Some of the image pairs were of a human face and an object (eg a beach ball), and others were of a human face with a scene (eg a beach).

Now and again the volunteers were asked to rest and simply think about anything they wanted, as long as they remained awake.

While the volunteers were tasked with looking at the images, and also during their rest breaks, the researchers took functional magnetic resonance images (fMRI) to gauge activity of their hippocampal and cortical regions. They also took a baseline reading before the volunteers were asked to look at images.

The results showed that:

• While the volunteers were looking at the image pairs (performing memory encoding tasks), the fMRIs showed signs of functional connectivity between the hippocampal and cortical brain (the lateral occipital complex or LO).


• This activity also occurred during the rest periods, sometimes at a higher level compared to baseline (boosted activity).


• However, boosted activity during rest only occurred following a memory encoding task that was well remembered in memory recall tests completed after the rest period.


• This effect did not appear during rest following memory encoding tasks where image pairs were poorly remembered in the later tests.


• Plus, as the authors wrote, the magnitude of hippocampal-LO correlations during post-task rest predicted individual differences in later associative memory.

Thus they concluded that:

"These results demonstrate the importance of postexperience resting brain correlations for memory for recent experiences."

Davachi said:

"Your brain is working for you when you're resting, so rest is important for memory and cognitive function."

"This is something we don't appreciate much, especially when today's information technologies keep us working round-the-clock," she added.

The National Institute of Mental Health and Dart Neuroscience helped pay for the study.

"Enhanced Brain Correlations during Rest Are Related to Memory for Recent Experiences."
Arielle Tambini, Nicholas Ketz, Lila Davachi.
Neuron, 65(2) pp. 280 - 290, 28 January 2010.
DOI: 10.1016/j.neuron.2010.01.001

Source: New York University.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
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